[John Jamieson]

Windmill power is proportional to V cubed.

Same as power required to push a car through the wind.

Car that takes 20hp to go 60 mph, takes 160hp to 120 mph.

[spunkets]

"Windmill power is proportional to V cubed."

Nah. Look at #1375 a little closer.

It's simple, so drag =1 there. Air is compressible, so real drag is < 1.

Only supersonic shock waves have v³.